1. Field of the Invention
The present invention relates to semiconductor stack structures and fabrication methods thereof, and more particularly, to a semiconductor stack structure having a plurality of wafers of different specifications and a fabrication method thereof.
2. Description of Related Art
Along with the rapid development of electronic industries, planar packaging technologies have reached their limits and hence integrating technologies are developed to meet the miniaturization requirement of electronic products. For the purpose of multi-function, a plurality of homogeneous or heterogeneous wafers are stacked.
However, a set of process equipment in a wafer packaging factory is specially used for processing a certain specification of wafers. To process a different specification of wafers, a different set of process equipment is required. For example, 8-inch equipment is used for processing 8-inch wafers and 12-inch equipment is used for processing 12-inch wafers. As such, newly developed electronic products need new equipment and even new factory buildings for processing, which adversely affects timely supply of chip packages and cannot meet the replacement speed of electronic products.
Therefore, there is a need to provide a semiconductor stack structure and a fabrication method thereof so as to overcome the above-described drawbacks.